I think these two should work together, but they haven't for me in a recent game. Normally when I think there's a bug someone explains to me here why they don't work.
Shepherd's Whistle "At the start of the breeding phase" you get a sheep
Champion Breeder "Each time you place 2 or 3+ animals on your farm during the breeding phase"
The start of the breeding phase is part of the breeding phase, so the shepherd's whistle sheep should count towards Champion Breeder? But it doesn't.
Shepherd's Whistle "At the start of the breeding phase" you get a sheep
Champion Breeder "Each time you place 2 or 3+ animals on your farm during the breeding phase"
The start of the breeding phase is part of the breeding phase, so the shepherd's whistle sheep should count towards Champion Breeder? But it doesn't.